Septic shock may be complicated by a state of immune suppression, with ominous prognosis significance. Although the underlying pathophysiological mechanisms are poorly understood, it is possible that norepinephrine, used to treat circulatory failure during septic shock, plays a significant contributing role. Indeed, besides its hemodynamic effects, norepinephrine exerts multiple immunosuppressive actions, which are primarily mediated by beta-2 adrenergic receptors expressed by immune cells. Furthermore, norepinephrine has the ability to promote the growth of numerous bacteria, and could thereby foster the development of nosocomial infections. Norepinephrine being one of the most prescribed drugs in intensive care medicine, knowledge of these particular immunological effects is essential for the intensive care physicians.